Pumpable potassium soaps



PABLE POTASSRM SOAPS Frank Pilch, Chicago, Ill., assignor to Armour and(Zompany, Chicago, 111., a corporation of Illinois No Drawing.Application July 5, 1952., Serial No. 297,399

7 Claims. (Cl. 252-432) This invention relates to soap making. Moreparticularly, this invention relates to resin acid soaps and to methodsof preparing the same.

As ordinarily produced, the potassium soaps derived from mixtures ofresin acids and fatty acids occur in the form of a viscous, stiff geland cannot be flowed or poured in a high solids form (i. e., greaterthan 30% solids) except at relatively high temperatures. Pumping of thesoap will not take place except at temperatures substantially in excessof 150 F.

Because of these unusual characteristics, it is difiicult to remove thesoap from containers, especially containers having restricted accessopenings. The problem is seen more clearly in connection with the tankcar shipment of potassium soap derived from fatty and resin acidmixtures. In this connection, it is highly impractical to unload thepotassium soap in solid form. Instead, it is usually satisfactory toconvert the soap to a fluid form so that it can be pumped from the tankcar. According to the usual method of unloading cars, an enclosed steamline is introduced into the tank and steam is blown through the lineuntil the soap contained in the tank is fluid. The fluid soap is thenpumped out of the tank while hot and is allowed to cool. Refrigerationis sometimes employed to facilitate the cooling of the soap.

This practice of unloading the soap has several disadvantages. First,the practice requires high capacity heating facilities at the point ofunloading. Such facilities are often unavailable, in which caseunloading of the soap is impractical. Also, the practice is timeconsuming and involves relatively large costs in heating andrefrigeration. Further, soap losses occur to some extent due to cakingand burning at the heat transfer surface. Not only is the soap damageddue to caking and burning but by reason of the burned soap forming in aninsulative I layer, the heat is prevented from diffusing properly intohired States atent method of producing readily pumpable potassium soapof mixtures of fatty and resin acids. to provide potassium soap of mixedfatty and resin acids which is capable of being pumped at a temperatureof 150 F. or lower. Another object of this invention is to provide afatty and resin acid soap which may be readily transferred fromcontainers. Still another object of this invention is to provide apotassium soap of fatty and resin acids which may be heated to a fluidpumpable condition without burning or discoloring the soap. Otherspecific objects and advantages will appear as this specificationproceeds.

This invention is based on the discovery that when the moisture and freeacid content of potassium soap de- Another object is 7 ice rived fromfatty and resin acid mixtures are maintained within critical limits, theobjectionable gelling characteristics are eliminated and the soap 150 F.or lower. I

The present invention may be more 'fully illustrated by the followingpreferred method of producing potassium soap, employing a mixture of 60%by weight resin acids (calculated as abietic acid), 32% fatty acids(calculated as oleic acid) and 8% unsaponifiable material. The mixtureemployed has a saponificatio-n value of 175.

Approximately 2000 pounds of the mixture just mentioned are mixedcontinuously in a crutcher with 725 pounds at 45% aqueous potassiumhydroxide. The run is started at about F., the temperature being allowedto rise during saponification to a finishing temperature of about 200 to210 F. The finished soap contains 17% moisture and 5% free acidcalculated as oleic, and consists largely of mixed potassium salts ofresin acids and fatty acids. The soap flows at room temperature and maybe readily pumped. At F. the soap is a smooth gel with highly fluidproperties.

Soaps produced in accordance with the present invention may be readilyflowed and pumped, it being required in some cases to heat the soapsmoderately to about 70 F. or higher, but in no case higher than F. Thepresent soaps not only are readily pumpable but also have a pronouncedresistance to burning when brought into contact with heated surfaces.lt'has been determined, upon heating the present soaps to a fluidcondition, that burning and caking are largely eliminated.

is readily pumpable at The present invention is applicable to mixturesof resin acids and fatty acids, particularly mixtures containing abieticacids, principally Steeles abietic acid, dehydroabietic acid,dihydroabietic acid, etc., and fatty acids containing 18 carbon atomssuch as oleic, linoleic, linolenic, etc. Suitably the resin acids forthese mixtures may be obtained from gum rosin, wood rosin, crude orrefined tall oil, or other source of resin acids. Similarly, the fattyacids may be obtained from animal or vegetable oils, tall oil, or othersuitable sources. Mixtures containing about 20 to 90% resin acids willgenerally be satisfactory. Preferably, the mixtures will contain from 40to 70% resin acids, and for optimum advantage, from 60 to 70%. Usually asmall amount of non-saponifiable material such as sterols, abietenes,etc., is associated with resin acids. The presence of a smallproportion, such as 5 to 15% by weight, of such material is notobjectionable for present purposes although. it is preferred toeliminate such material altogether or at least to maintain such materialat a minimum, as for example 5% or lower. The remaining portion of theapplicable mixtures consists essentially of. fatty acids having 18carbon atoms, particularly oleic, linoleic and linolenic acids. Smallamounts of higher and lower fatty acids (as for example adjacenthomologs) may also be present. The saponification value of the mixturesemployed may be from 150 to 200 and preferably from to 185.

Since certain of the acids contemplated by the present invention areunstable and tend to break down when subjected to heat, air, etc., it isconsidered desirable in some cases to convert the acids to a stable acidform prior to saponification. Steeles abietic acid, in particular, isrelatively unstable, and it is usually desirable therefore to convertSteele's acid to a more stable form prior to saponification. It will beconvenient in effecting stabilization, to subject the mixture of fattyand resin acids to tion is not necessary to the practice of the presentinven tion, since satisfactory soaps may be prepared from mixtures whichhave not been stabilized.

I have found it important in the composition of the.

' range of 1510 22% moisture.

pumpable gel.

if weight) of free acid.

present soaps, to maintain the proportions of moistureand' free acidwithin narrow limits. For satisfactory results, the free acid content(calculated as oleic acid) may be from .about 4 to of the total weightof the soap and, preferably, from 4 to 6%. V The moisture content maybefrom about to 22% of the total weight and,

preferably, from 16 to 18%. For example, a preferred soap will contain17% moisture by weight, the balance being solids, of which 5% consistsof free acid calculated as oleic acid. Proportions of moisture or freeacid greater or lesser than those set forth result in a stiff gel thatcan be pumped only at temperatures substantially in excess of 150 F. Forexample,.a potassium soap preparedfronr mixed fatty and resinacidstresin acid, 60%; fatty acid,

%; unsaponifiable, 5%) and containing 3% moisture is a stiff gel thatcannot be pumped. Addition of mois:

ture to such a soap makes it fluid and pumpable in the Further additionof moisture causes the soap to set up into a, non-fluid gel which cannotbe pumped. By way of example, a soap of this type containing 30%moisture is an extremely heavy, un-

As a saponifying or neutralizing agent, any potassium alkali may beused, especially potassium hydroxide (caustic .potash),.potassiumcarbonate (pearl ash), and mixtures thereof. The use ofpotassiumhydroxide is preferred. Preferably, for acid materials having asaponification value of about 175, the potassium'hydroxide (KOH) andacid material are employed in the weight ratio of 1:6, these proportionsserving to provide in the finished soap a free acid content of from 4 to10% by weight. Of course, it is understood that where the saponificationvalue of the acid material is higherfor V lower) than 175,correspondingly higher (or lower) proportions of KOH are necessary inorder "to provide in the finished soap the desired'amount (i. .-e., 4 to10%. by

It is advantageous to employ the 'saponifying agent in the form of anaqueous solution or slurry of aconcentration sufficient to provide thedesired saponifying action and to further provide the moisturecontent'desired in the finished soap. For example, it is' convenient tocmploya to aqueous potassium hydroxide solution in an amount sufficientto neutralize about 95% of the acid content, thereby leaving the desiredcontent of acid in the finished soap. In such a case, the

amount of. moisture escaping from the crutcher due to evaporation issuch that the final moisture content in the finished soap ordinarilyfalls within the desired range.

Of course it will be apparent that ina case where the' moisture or acidcontent of the soapdoes not fall within the desired limits, it will besatisfactory to make adjustduring saponification is important.

finishes. If saponification is found to be incomplete, ad.- ditionalsaponifying agent may be charged to the crutcher, care being'taken toassure a final free acid content of from 4 to 10%. Likewise, themoisture may be adjusted to assure a final moisture content of fromabout 15 to Thorough mixing or agitation of the soap materials 35% fattyacids, and 5% unsaponifiable materials; saponification value, 180) and258, pounds ofpearl ash in aqueous solution, are charged to a crutcherat about 175 .F. Mixing is started, and 0.02 pound of anti-foaming agent(Dow-CorningAnti-Foam.A) are added. Mixing is continued untilsaponification is 85% complete. An excess 'of pearl ash is addedtocomplete the saponification to" 95%, the final moisture being 18% byweight. The

7 resulting soap is a soft solid at 85 F. and is fluid and pumpable at150 F. While in the foregoing specification various details of thisinvention have been set forthfor the purpose of illustration, it will beapparent that such details may be merit to within these limits byreducing or increasing the moisture or adding acid or alkali, 'as thecase may be. In any case, provision of a satisfactory soap in accordancewith the present invention may be considered as involving the step ofneutralizing and the step of adjusting the acid contentand moisturecontent, but of course it will be more convenient to provide the correctproportions of ingredients (alkali, acid and water) prior toneutralization sothat adjustment of the proportions-of these ingredientsis accomplished automatically in connection with neutralization. 1

I Inthe use of pearl ash, it is found thata considerable amount .offoaming is produced during saponification. desired, the foaming may bereduced through the use of any suitable anti-foaming agent; Thetemperature of saponification is not at all critical. The reaction willproceed at room temperature. Generally, however, it will be preferred tosupply moderate heatat the start of a run in order to initiate thereaction and, since the reaction is exothermic, it is not necessary tosupplyfurther heat oncethe reaction has started. Usually a run isstarted by heating the charge to about 90 to 125 F. and, owing to heatof saponification, the temperature'rise's to about'200 to 210 F.beforethe soap,

varicdwidely by those skilled in the art without departing from thespirit of the invention. 1 claim:

lQA soap-making process, comprising heating a mixture of resin acids andhigher fatty acids with potassium alkali at a saponifyingtemperature inthe presence of water to cause substantial neutralization of said acidstherebyv providing a potassium soap, said mixture containing about20 toby weight resin acids and having a saponification value of about to 200,and adjusting the free acid content, calculated as oleic acid andmoisture content of said soap to about 4 to '10% and r bout 15 to 22% byweight respectively.

2. in the method of producing a pumpable potassium soap, the steps ofagitating at a saponifying temperature a mixture of resin acids andhigher fatty acids, said mixture having a saponification value of about.and con tainingabout 20 to 90% by weight resin acids, and potassiumhydroxide inthe weight ratio of about 6 ml in the presence of water tocause neutralization of said acids, thereby providing a 'soap'containingabout 4 to- 10% free acid calculated as oleic acid, and adjustingthernoisture content of said by weight moisture.

3. A method of producing soap comprising mixing refined-tall oilcontaining higher fatty acids and 20 to 90% by weightresin acids andhaving a saponification value of about 175 with caustic potash in theweight ratio of about 6 to 1 in the presence of water at a temperatureof at least 70 Fl to cause neutralization of the caustic potash and ,toprovide an excess of free acid of about 4 to 10 Weight per cent,calculated as oleic acid, and adjusting the water content of the mixtureto about 15 to 22% by weight.

4. A pumpable potassium soap, comprising potassium salts of resin acidsand higher fatty acids contained in a tall oil fraction having asaponification value of 160 to and'a resin acid content of from 20 to90% by weight, in admixturewith 4 to 10% free acid, calculated as oleicacid and 15 to 22% moisture. t

5. A fluid soap material comprising potassium salts of resin and higherfatty acids contained in a mixture of resins and higher fatty acidshaving a saponification value' The mixing serves soap to about 15 to 22%of about 150 to 200 and a resin acid content of 20 to 90 per cent byWeight, in admixture with 4 to 10 per cent by Weight of free acidcalculated as oleic acid and 15 to 22 per cent moisture.

6. A fluid soap material comprising potassium salts of resin and higherfatty acids contained in a mixture of resin and higher fatty acidshaving a saponification value of about 150 to 200 and a resin acidcontent of 40 to 70 per cent by weight, in admixture with 4 to 10 percent by weight of free acid calculated as oleic acid and 15 to 22 percent moisture.

7. A fluid soap material comprising potassium salts of resin and higherfatty acids contained in a mixture of resin and higher fatty acidshaving a saponification value of about 180, a resin acid content ofabout 60 per cent by weight, a higher fatty acid content of about 35 percent by weight, and an unsaponifiable content of 5 per cent by Weight,in admixture with 5 per cent free acid calculated as oleic acid and 18per cent moisture.

References Cited in the file of this patent FOREIGN PATENTS

5. A FLUID SOAP MATERIAL COMPRISING POTASSIUM SALTS OF RESIN AND HIGHERFATTY ACID CONTAINED IN A MIXTURE OF RESINS AND HIGHER FATTY ACIDSHAVING A SAPONIFICATION VALUE OF ABOUT 150 TO 200 AND A RESIN ACIDCONTENT OF 20 TO 90 PER CENT BY WEIGHT, IN ADMIXTURE WITH 4 TO 10 PERCENT BY WEIGHT OF FREE ACID CALCULATED AS OLEIC ACID AND 15 TO 22 PERCENT MOISTURE.